The present invention relates to a radial load reducing device for reducing a radial load to be applied to a rotating shaft, and also relates to a sliding bearing and a screw compressor using the same.
In case of a screw compressor for example, a rotor shaft receives a large thrust load and radial load from a high-pressure side to a low-pressure side because of a compressed gas enclosed by a screw rotor. Accordingly, the rotor shaft is supported by a thrust bearing and a radial bearing.
The life of such bearings decreases with an increase in such loads to be applied to the bearings.
There has been proposed a device for reducing the thrust load to be applied to the rotor shaft of the screw compressor and thereby extending the life of the thrust bearing (Japanese Patent Publication No. 48-33041 and Japanese Patent Laid-open Publication No. 57-153986).
However, any measures for reducing the radial load to be applied to the radial bearing has not yet been practically applied at present.
The operation of the screw compressor is limited depending upon the life of the radial bearing, and any screw compressor at present cannot be operated under a high-pressure greater than a given discharge pressure. Thus, it is greatly demanded to expand an applicable pressure range of the screw compressor.